Afghanistan Warinternational conflict in Afghanistan beginning in 2001 that was triggered by the September 11 attacks and consisted of three phases. The first phase—toppling the Taliban (the ultraconservative political and religious faction that ruled Afghanistan and provided sanctuary for al-Qaeda, perpetrators of the September 11 attacks)—was brief, lasting just two months. The second phase, from 2002 until 2008, was marked by a U.S. strategy of defeating the Taliban militarily and rebuilding core institutions of the Afghan state. The third phase, a turn to classic counterinsurgency doctrine, began in 2008 and accelerated with U.S. Pres. Barack Obama’s 2009 decision to dramatically increase the U.S. troop presence in Afghanistan. The larger force was used to implement a strategy of protecting the population from Taliban attacks and supporting efforts to reintegrate insurgents into Afghan society. By mid-2010 the Afghanistan War rivaled the Vietnam War as the longest war fought by the United States.

Prelude to the September 11 attacks

The joint U.S. and British invasion of Afghanistan in late 2001 was preceded by over two decades of war in Afghanistan. On Dec. 24, 1979, Soviet tanks rumbled across the Amu Darya River and into Afghanistan, ostensibly to restore stability following a coup that brought to power a pair of Marxist-Leninist political groups—the People’s (Khalq) Party and the Banner (Parcham) Party. But the Soviet presence touched off a nationwide rebellion by Islamist fighters, who won extensive covert backing from Pakistan, Saudi Arabia, and the United States and who were joined in their fight by foreign volunteers. The guerrilla war against the Soviet forces led to their departure a decade later (see Afghan War). In the void, civil war reigned, with the Islamist fighters—known as the mujahideen—battling first to oust the Soviet-backed government and then turning their guns on each other.

In 1996 the Taliban seized Kabul and instituted a severe interpretation of Islamic law that, for example, forbade female education and prescribed the severing of hands, or even execution, as punishment for petty crimes. That same year, al-Qaeda leader Osama bin Laden was welcomed to Afghanistan (having been expelled from Sudan) and established his organization’s headquarters there. With al-Qaeda’s help, the Taliban won control of over 90 percent of Afghan territory by the summer of 2001. On September 9 of that year, al-Qaeda hit men carried out the assassination of famed mujahideen leader Ahmad Shah Massoud, who at the time was leading the Northern Alliance (a loose coalition of mujahideen militias that maintained control of a small section of northern Afghanistan) as it battled the Taliban and who had unsuccessfully sought greater U.S. backing for his efforts.

The September 11 attacks and the U.S.-British invasion

The hijacking and crashing of four U.S. jetliners on Sept. 11, 2001, brought instant attention to Afghanistan. The plot had been hatched by al-Qaeda, and some of the 19 hijackers had trained in Afghanistan. In the aftermath of the attacks, the administration of U.S. Pres. George W. Bush coalesced around a strategy of first ousting the Taliban from Afghanistan and dismantling al-Qaeda, though others contemplated actions in Iraq, including long-standing plans for toppling Pres. Ṣaddām Ḥussein. Bush demanded that Taliban leader Mullah Mohammed Omar “deliver to [the] United States authorities all the leaders of al-Qaeda who hide in your land,” and when Omar refused, U.S. officials began implementing a plan for war.

The campaign in Afghanistan started covertly on September 26, with a Central Intelligence Agency (CIA) team known as Jawbreaker arriving in the country and, working with anti-Taliban allies, initiating a strategy for overthrowing the regime. U.S. officials hoped that by partnering with the Afghans they could avoid deploying a large force to Afghanistan. Pentagon officials were especially concerned that the United States not be drawn into a protracted occupation of Afghanistan, as had occurred with the Soviets more than two decades prior. The United States relied primarily on the Northern Alliance, which had just lost Massoud but had regrouped under other commanders, including Tajik leader Mohammed Fahim and Abdul Rashid Dostum, an Uzbek. The Americans also teamed with anti-Taliban Pashtuns in southern Afghanistan, including a little-known tribal leader named Hamid Karzai.

The CIA team was soon joined by U.S. and British special forces contingents, and together they provided arms, equipment, and advice to the Afghans. They also helped coordinate targeting for the air campaign, which began on Oct. 7, 2001, with U.S. and British war planes pounding Taliban targets, thus marking the public start of Operation Enduring Freedom. In late October, Northern Alliance forces began to overtake a series of towns formerly held by the Taliban. The forces worked with U.S. assistance, but they defied U.S. wishes when, on November 13, they marched into Kabul as the Taliban retreated without a fight.

Kandahar, the largest city in southern Afghanistan and the Taliban’s spiritual home, fell on December 6, marking the end of Taliban power. It had been besieged by a force led by Karzai that moved in from the north and one commanded by Gul Agha Sherzai that advanced from the south; both operated with heavy assistance from the United States. As the Taliban leadership retreated into Afghanistan’s rural areas and across the border to Pakistan, anti-Taliban figures convened at a United Nations (UN)-sponsored conference in Bonn, Ger. With behind-the-scenes maneuvering by the United States, Karzai was selected to lead the country on an interim basis.

Despite an intensive manhunt for Omar, bin Laden, and al-Qaeda deputy chief Ayman al-Zawahiri, none of them was captured or killed. The Americans are believed to have come closest to bin Laden in the December 2001 battle of Tora Bora (bin Laden’s mountain stronghold). But bin Laden is thought to have managed to have slipped into Pakistan with the help of Afghan and Pakistani forces that were supposedly helping the Americans. Critics later questioned why the U.S. military had allowed Afghan forces to lead the assault on the cave complex at Tora Bora rather than doing it themselves. (Indeed, Democratic presidential candidate Sen. John Kerry made this criticism repeatedly during the 2004 general election campaign.) Al-Qaeda subsequently reestablished its base of operations in the tribal areas that form Pakistan’s northwest border with Afghanistan. Omar and his top Taliban lieutenants settled in and around the Pakistani city of Quetta, in the remote southwestern province of Balochistān. One of the final major battles of the first phase of the war came in March 2002 with Operation Anaconda in the eastern province of Paktia, which involved U.S. and Afghan forces fighting some 800 al-Qaeda and Taliban militants. The operation also marked the entrance of other countries’ troops into the war: special operations forces from Australia, Canada, Denmark, France, Germany, and Norway participated.

Iraq takes centre stage

With the ouster of the Taliban and al-Qaeda, the international focus shifted to reconstruction and nation-building efforts in Afghanistan. In April 2002 Bush announced a “Marshall Plan” for Afghanistan in a speech at the Virginia Military Institute, promising substantial financial assistance. But from the start, development efforts in Afghanistan were inadequately funded, as attention had turned among U.S. officials to the looming confrontation in Iraq. Between 2001 and 2009, just over $38 billion in humanitarian and reconstruction assistance to Afghanistan was appropriated by the U.S. Congress. More than half the money went to training and equipping Afghan security forces, and the remainder represented a fraction of the amount that experts said would be required to develop a country that had consistently ranked near the bottom of global human development indices. The aid program was also bedeviled by waste and by confusion over whether civilian or military authorities had responsibility for leading education, health, agriculture, and other development projects.

Despite military commitments from dozens of U.S. allies, the United States initially argued against allowing the other foreign forces—operating as the International Security Assistance Force (ISAF)—to deploy beyond the Kabul area. That choice was directed by the Pentagon, which insisted on a “light footprint” out of concern that Afghanistan would become a drag on U.S. resources as attention shifted to Iraq (see Iraq War). When ISAF did begin to venture beyond Kabul, its efforts were hampered by the “caveats” of its component countries—restrictions that kept all but a handful of the militaries from actively engaging in the fight against the Taliban and al-Qaeda. The force, overseen by the North Atlantic Treaty Organization (NATO) in the organization’s first mission outside Europe, was also hamstrung by a lack of troops as international commitments to Afghanistan flagged.

The United States consistently represented the largest foreign force in Afghanistan, and it bore the heaviest losses. By spring 2010 more than 1,000 U.S. troops had been killed in Afghanistan, while the British troops suffered some 300 deaths and the Canadians some 150. Both Britain and Canada stationed their troops in Afghanistan’s south, where fighting had been most intense. More than 20 other countries also lost troops during the war, though many—such as Germany and Italy—chose to focus their forces in the north and the west, where the insurgency was less potent. As the fighting dragged on and casualties escalated, the war lost popularity in many Western countries, creating domestic political pressure to keep troops out of harm’s way or to pull them out altogether.

Initially the war appeared to have been won with relative ease. On May 1, 2003, U.S. Secretary of Defense Donald Rumsfeld announced an end to “major combat” in Afghanistan. On the same day, aboard the aircraft carrier USS Abraham Lincoln, President Bush announced that “major combat operations in Iraq have ended.” At that time, there were 8,000 U.S. troops in Afghanistan. The first democratic Afghan elections since the fall of the Taliban were held on Oct. 9, 2004, with approximately 80 percent of registered voters turning out to give Karzai a full five-year term as president. Parliamentary elections were staged a year later, with dozens of women claiming seats set aside for them to ensure gender diversity. The 2004 constitution provided Afghanistan with a powerful central government and weak regional and local authorities—a structure that was in opposition to the country’s long-standing traditions.

Despite vast powers under the constitution, Karzai was widely regarded as a weak leader who grew increasingly isolated as the war progressed. He survived several assassination attempts—including a September 2004 rocket attack that nearly struck a helicopter he was riding in—and security concerns kept him largely confined to the presidential palace in Kabul. Karzai’s government was beset by corruption, and efforts to build a national army and a police force were troubled from the start by inadequate international support and ethnic differences between Afghans.

Taliban resurgence

Beginning in 2005, violence climbed as the Taliban reasserted its presence with new tactics modeled on those being used by insurgents in Iraq. Whereas early in the war the Taliban had focused on battling U.S. and NATO forces in open combat—a strategy that largely failed to inflict significant damage—their adoption of the use of suicide bombings and buried bombs, known as IEDs (improvised explosive devices), began to cause heavy casualties. Between January 2005 and August 2006, Afghanistan endured 64 suicide attacks—a tactic that had been virtually unknown in the country’s history before then. At first the attacks caused relatively few casualties, but as training and the availability of high-powered explosives increased, the death toll began to climb: in one particularly vicious attack in November 2007, at least 70 people—many of them children—were killed as a parliamentary delegation visited the northern town of Baghlan. Less than a year later, a bombing at the Indian embassy in Kabul killed more than 50; the Afghan government accused elements of Pakistan’s intelligence service of complicity in the attack, a charge Pakistan denied.

The Taliban’s resurgence corresponded with a rise in anti-American and anti-Western sentiment among Afghans. Those feelings were nurtured by the sluggish pace of reconstruction, allegations of prisoner abuse at U.S. detention facilities, widespread corruption in the Afghan government, and civilian casualties caused by U.S. and NATO bombings. In May 2006 a U.S. military vehicle crashed and killed several Afghans, an event that sparked violent anti-American riots in Kabul—the worst since the war began. Later that year NATO took command of the war across the country; American officials said that the United States would play a lesser role and that the face of the war would become increasingly international. This shift reflected the greater need for U.S. troops and resources in Iraq, where sectarian warfare was reaching alarming levels. By contrast, the war in Afghanistan was still regarded in Washington as a relative success.

For commanders on the ground in Afghanistan, however, it was apparent that the Taliban intended to escalate its campaign. The Taliban was earning ample money through donations from wealthy individuals and groups in the Persian Gulf and from the booming opium trade. While poppy cultivation had been dramatically curbed during the Taliban’s final year in power, the group pushed to revive cultivation as a means of funding its insurgency. Western-backed campaigns to eliminate poppy cultivation or to encourage farmers to grow other crops had little discernible impact; Afghanistan soon became the supplier of over 90 percent of the world’s opium.

The United States, meanwhile, had had only limited success in killing or capturing Taliban commanders. In early 2007, Mullah Obaidullah Akhund—the Taliban’s number three leader—was captured in Pakistan, and months later Mullah Dadullah—the Taliban’s top military commander—was killed in fighting with U.S. forces. But those were the exceptions. Top insurgent leaders remained at large, many of them in the tribal regions of Pakistan that adjoin Afghanistan. This reality prompted the United States to begin targeting insurgent leaders who lived in Pakistan with missiles fired from remotely piloted drones (see unmanned aerial vehicle). The CIA program of targeted killings was publicly denied by U.S. officials but was widely acknowledged in private. Pakistani officials in turn denounced the strikes in public but privately approved of them as long as civilian casualties were limited. The United States repeatedly threatened to expand its drone strikes beyond Pakistan’s tribal areas and into regions such as Balochistān if Pakistan did not demonstrate greater cooperation in battling the Taliban, a group it had long fostered.

The Obama surge

U.S. Pres. Barack Obama went to the White House promising to focus attention and resources on the faltering war effort in Afghanistan. On Feb. 17, 2009, he approved sending an additional 17,000 U.S. troops, on top of the 36,000 U.S. troops and 32,000 NATO service members already there. Three months later Obama took the rare step of removing a commanding general from a theatre of war, replacing Gen. David McKiernan with Gen. Stanley McChrystal. While McKiernan was shifting U.S. strategy in Afghanistan, Obama and other top officials had concluded that a more radical change was needed. McChrystal was brought in to implement a new strategy modeled after the surge strategy in Iraq—one in which U.S. forces would focus on protecting the population from insurgents rather than simply trying to kill large numbers of militants. The strategy also involved trying to persuade enemy fighters to defect and ultimately encouraging reconciliation between the Karzai government and Taliban leaders.

Soon after assuming command, McChrystal concluded that he did not have enough troops to execute the new strategy, and in September 2009 he laid out his concerns in a confidential report, which was subsequently leaked to the press. McChrystal predicted that the war would be lost within a year if there was not a significant troop surge. After an intensive Afghan policy review—the second one by the Obama administration in less than a year—the president delivered a speech at the U.S. Military Academy at West Point on December 1 in which he announced a major escalation in the war effort, with 30,000 additional troops being deployed to Afghanistan by the summer of 2010. The new strategy led to an increase in U.S. combat deaths; notably, during the first three months of 2010, U.S. deaths were approximately twice what they had been over the same period in 2009.

The surge in U.S. forces was accompanied by a dramatic escalation of U.S. drone strikes in Pakistan—one of which killed Pakistani Taliban leader Baitullah Mehsud. But the CIA also paid a price in late December 2009 when an al-Qaeda double agent detonated a suicide bomb at a Bagram air base in the eastern province of Khost, killing seven from the agency.

In early 2010 the surge began with an assault on the insurgent-held town of Marja, in the southern province of Helmand. U.S. Marines achieved a relatively quick victory, even as McChrystal planned a more ambitious offensive in Kandahar. Obama visited Afghanistan for the first time as president on March 28, delivering a stern message to Karzai that he needed to clean up corruption in his government. Karzai had won a new five-year term in an August 2009 election that was tainted by widespread allegations of fraud. Karzai vowed in his inaugural address to stamp out corruption in his government, but there were few signs in the short term that he had done so.

Meanwhile, Karzai announced that he would attempt to reconcile with the Taliban; he repeatedly invited Mullah Omar to meet with him, but the Taliban leader steadfastly refused. Under intense pressure from the United States, Karzai lashed out in April 2010 and even threatened to join the Taliban if the international community did not stop meddling in Afghan affairs. Troubled by the comments, the White House threatened to revoke Karzai’s invitation to meet with Obama in Washington, D.C., but the visit occurred as scheduled, with Karzai and Obama at least outwardly making efforts to mend their relationship.

Pakistan offered to mediate Afghan peace talks, but Pakistan’s ultimate attitude toward the Taliban remained a matter of great controversy. In February 2010, Pakistani security forces arrested the Afghan Taliban’s second-in-command, Mullah Abdul Ghani Baradar, a move interpreted by many U.S. officials as a reflection of Pakistan’s desire to work with the U.S. and Afghan governments to stem the group’s influence. But others, including Kai Eide, the former top UN official in Kabul, said Baradar had been a leading Taliban proponent of reconciliation and that the arrest was intended to scuttle efforts to end the war through a political, rather than a military, solution.

The military command structure in Afghanistan abruptly changed again in June 2010, when Obama replaced McChrystal with Gen. David Petraeus after McChrystal and some of his aides made disparaging remarks to a Rolling Stone magazine reporter about Obama and other top administration officials, including Vice Pres. Joe Biden, National Security Adviser James L. Jones, and special representative to Afghanistan Richard Holbrooke.